Waterproof shoe

ABSTRACT

A waterproof, water vapor permeable shoe having a waterproof, water vapor permeable functional layer, an upper, and a lining. The functional layer may be made from a dispersion of a waterproof, water vapor polymer. The functional layer may only be attached to the lining at the top opening of the shoe.  
     A method of making a waterproof, water vapor permeable shoe by forming a waterproof, water vapor permeable functional layer from a dispersion of a waterproof, water vapor permeable polymer and then attaching the functional layer to the lining of the top opening of the shoe.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] This invention relates to a waterproof shoe constructed from awaterproof, water vapor permeable layer.

[0003] 2. Description of Related Art

[0004] Shoes made from waterproof, water vapor permeable materials arewell known. Waterproof, water vapor permeable shoes may be manufacturedusing a variety of materials and processes. Typically, waterproof, watervapor permeable shoes are manufactured using a laminate material toimpart waterproof, water vapor permeable characteristics to the shoe.The laminate material is often used in conjunction with other materials,well known in the art, that provide the exterior portions (such as, forexample, the upper or the sole) and interior portions of the shoe (suchas, for example the lining). The laminate material used to impartwaterproof, water vapor permeable properties to the shoe is typicallymade from a functional layer, which imparts the waterproof, water vaporpermeable characteristics, and at least one more layer of othermaterials or textiles.

[0005] The construction of waterproof, water vapor permeable shoes froma laminate material is very expensive and labor intensive, as nearlyevery seam that is sewn in the process of making the shoe must beresealed to attempt to maintain a waterproof, water vapor permeableshoe.

[0006] Various types of waterproof, water vapor permeable shoe designsare known. A first common method is to simply construct the shoe fromknown materials in conjunction with waterproof, water vapor permeablematerials (i.e., a waterproof, water vapor permeable laminate) andperform the aforementioned requisite seam sealing using a seam sealingtape, glue or other process to maintain a waterproof shoe design. Asecond common method to manufacture waterproof, water vapor permeableshoes is to manufacture a waterproof, water vapor permeable sock-likeliner which is subsequently inserted and attached to the remainder ofthe shoe. The three dimensional sock-like liners are manufactured from awaterproof, water vapor permeable laminate and require extensive sewingto create a three dimensional sock-like liner out of a flat sheet of thelaminate. Every seam that is sewn to create the sock-like liner must beresealed to attempt to the maintain waterproof, water vapor permeablecharacteristics of the shoe.

[0007] A waterproof, water vapor permeable laminate may be manufacturedby gluing together at least two layers, for example, a functional layerand a second layer made from a textile fabric or other material. Thefunctional layer is typically the waterproof, water vapor permeablelayer. The second or subsequent layers are generally water vaporpermeable and not waterproof. At the areas where glue is located betweenthe functional layer and second layer, the glue hinders the water vaporpermeability of the laminate. Therefore, in the manufacture oflaminates, efforts have focused on gluing the functional layer and thesecond layer together only at points necessary to maintain the integrityof the laminate. However, significant areas still remain where gluecovers the functional layer, and at these points, the functionality ofwater vapor permeability is reduced or eliminated.

[0008] It is often difficult to guarantee waterproofing and water vaporpermeability in either of these type of shoe designs, even when theseams have been resealed, because every seam which is sewn into thelaminate can transport water to the inside of the shoe via capillaryaction. Furthermore, the use of sealant often detracts from thewaterproof, water vapor permeable design of the shoe because thesealant, such as tape or glue, is not typically waterproof, water vaporpermeable. Portions of the shoe in which sealant are applied typicallylose their waterproof, water vapor permeable properties.

[0009] Using either of these above-described methods to manufacturewaterproof, water vapor permeable shoes also requires that differentsized liners be manufactured to obtain different sized shoes. Requiringa different sized liner for different sized shoes increases productioncosts.

[0010] There are illustrated in WO 95/30793 waterproof, breathable,flexible, seamless shaped articles made from a first layer of amicroporous, elastomeric, thermoplastic polyester polyurethane orpolyether polyurethane that is water vapor permeable and a second layerof a hydrophilic, continuous non-porous polymer layer that is waterproofand water vapor permeable.

[0011] There is illustrated in EP 0 665 259 A1 a process formanufacturing waterproof, water vapor permeable three dimensionalarticles made by treating a 3-dimensional mold with an aqueousdispersion of a copolyether ester at least once in a manner, analogousto that employed for a latex dispersion in the rubber industry, followedby heating to obtain a film.

[0012] There is illustrated in U.S. Pat. No. Re. 34,890 a shoeconstruction comprising a sole, an upper and a separate sock-like linercomprised of a laminate of at least three layers. The liner may besecured by stitching and thereafter covered with tape and athermoplastic resin adhesive. Heat and pressure are then applied to theseam of the liner covered with tape and adhesive. This processwaterproofs the stitching of the seam of the liner. The seams of thisinvention may also be formed without stitching instead usingelectro-disealing and adhesives.

[0013] As described above, there is still a need for a waterproof, watervapor permeable shoe design that overcomes the above-describedobstacles.

SUMMARY OF THE INVENTION

[0014] It is an object of the invention to provide for a waterproof,water vapor permeable shoe design that avoids problems of laminatedlayers and reduces the necessity to seal the seams in the waterproof,water vapor permeable portions of the shoe.

[0015] It is a further object of the invention to provide a moreeconomical and efficient waterproof, water vapor permeable shoe designby reducing the necessity for various sized liners and for a reductionin the time spent in the process of manufacturing the liner.

[0016] These and other objects of the present invention are achievedherein. In the invention, a waterproof, water vapor permeable shoe ismanufactured from the incorporation of a waterproof, water vaporpermeable functional layer into the shoe design. The sock-likefunctional layer is not attached to the liner except at the top openingof the shoe, i.e., the upper portion of the upper. The sock-likefunctional layer is separate from the lining and the upper and is not alaminate. The waterproof, water vapor permeable functional layer may beformed from a solution or a dispersion of a waterproof, water vaporpermeable polymer.

[0017] The shoe construction of the present invention provides awaterproof, water vapor permeable shoe with no or a reduced risk oflosing its waterproof, water vapor permeability. The shoe constructionof the present invention accomplishes these objectives by providing fora seamless or virtually seamless functional layer that obviates orreduces the need for seams or seam-sealing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a cross-sectional view from the side of the shoe.

[0019]FIG. 2 is a cross-sectional view from the side of the shoe havingan injection molded sole.

[0020]FIG. 3 is a view from the bottom of the sock-like functional layershowing a cut in the bottom of the functional layer.

[0021]FIG. 4 is a view of the cut ends of the functional layer beingconnected.

[0022]FIG. 5 is a view of the cut ends of the functional layer beingconnected with glue over tape.

[0023]FIG. 6 is a view from the front of a the sock-like functionallayer in which the bottom of the functional layer has been removed andreplaced with an insole.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] The present invention provides a waterproof, water vaporpermeable shoe design in which a waterproof, water vapor permeablefunctional layer is formed from a dispersion or solution of waterproof,water vapor permeable polymer. The functional layer is in the shape of asock and is then is incorporated into the shoe.

[0025] The present invention provides a waterproof, water vaporpermeable shoe design comprising 1) a waterproof, water vapor permeablefunctional layer produced by dipping a foot shaped, solid form into adispersion or a solution of waterproof, water vapor permeable polymerand allowing the form to dry and harden and then peeling the sock-likefunctional layer from the form, and 2) attaching the functional layer tothe lining of a shoe wherein the attachment is at least at the openingof the shoe.

[0026] The sock-like functional layer is inserted into the uppermaterial, a lining is inserted into the functional layer, and finally asole is incorporated onto the bottom portions of the upper materialand/or the functional layer. The functional layer may only be connectedto the lining near the opening of the shoe. Optionally, the lining maybe inserted into the functional layer, before the functional layer isinserted into the upper.

[0027] In other embodiments, the present invention provides a shoeconstruction where, prior to insertion into the upper, an opening may becut into the bottom of the functional layer to further increase theadaptability of the functional layer. Once an opening has been cut intothe functional layer, portions of the functional layer may be removedfrom the opening and the edges of the opening may then be reconnected.By removing portions of the functional layer, a smaller-sized functionallayer is made without using different sized forms. Additionally, once anopening has been made in the functional layer, an insole may be insertedinto the opening to increase adaptability of the functional layer.

[0028] The present invention provides a process for manufacturingwaterproof, water vapor permeable shoes by forming a functional layerfrom a dispersion of a waterproof, water vapor permeable polymer,inserting the functional layer into an upper, inserting a lining intothe functional layer, and attaching the functional layer to the liningat least at the top opening of the shoe. Optionally, the lining may beinserted into the functional layer before the functional layer isinserted into the upper.

[0029]FIG. 1 shows a shoe of the present invention having an upper 1, afunctional layer 2, a lining 3, and a sole 5. The functional layer 2 iswaterproof and water vapor permeable and is situated between the upper 1and the lining 3.

[0030] The functional layer 2 is preferably attached only at the topportion of the upper 1, i.e., the top opening where a foot of a weareris inserted into the shoe. In a preferred embodiment, the portion of theupper near the opening of the shoe shown in FIG. 1 is folded over theends of the functional layer 2 and the lining 3 and fixed over a seam 4.This connection between the functional layer 2 and the lining 3 near theopening of the shoe is preferably the only connection between thefunctional layer 2 and the lining 3.

[0031] The functional layer 2 is in the shape of a sock and is notbonded with the lining with the exception of at the opening of the shoe.At the bottom of the shoe, the upper 1 is bonded to the sole 5,preferably over a seam and/or over a glue. The part of the functionallayer adjacent to the sole may be bonded, preferably using glue or asewing technique, to the sole. If the functional layer is sewn to thesole, the outer contour of the sole may be sewn to the functional layerand the holes in the functional layer may be resealed by anotherapplication of waterproof, water vapor permeable polymer.

[0032] In another embodiment of the present invention, injection moldedshoe designs are possible. See, for example, U.S. Pat. No. 5,930,917,incorporated by reference herein. FIG. 2 shows a construction of a shoeof the present invention whereby the sole 6 is injection molded. In thecase of injection molded soles, the material that is injected to formthe sole may fill and seal any seams or other breaches (caused bymanufacturing) in the waterproof, water vapor permeable functionallayer. Therefore, the seams caused by a cut in the functional layer,either to increase size adaptability or to insert an insole, may notrequire further glue and tape to maintain waterproofness. In thisconstruction, the functional layer 2 is bonded to the injection moldedmaterial.

[0033] Surprisingly, a separate form is not necessary for every shoesize or style because of the relative thinness of the functional layer.When the functional layer is incorporated into a shoe, the folds andcreases the functional layer makes as it conforms to the interiorportions of the shoe are not noticed by the wearer of the footwear sincethe material forming the functional layer is relatively thin, i.e., 10to 150 microns. One particular size functional layer may be incorporatedinto many different sizes of shoes. This interchangeability of thefunctional layer reduces manufacturing costs as a separate sized lineris not required to be manufactured for each individual shoe size.

[0034] The upper 1, lining 3, and the sole 5 may be selected frommaterials well known in the art. See, for example, U.S. Pat. No.5,678,326, incorporated herein by reference. The upper 1 may be madefrom, for example, leather, textiles, woven fabrics, canvas, fabric,chintz, everglaze, terry, velvet, Manchester velvet, corduroy,velveteen, Norzon, leatherette, muslin, duvetine, satin, fur, imitationfur, suede leather, satin finish leather, patent leather or polished,embossed, shrunk or grained leather.

[0035] The lining 3 may be made from, for example, terry, goat skin,sheep skin, cowhide, pig skin, velvet, camel hair, fabric, knitted orwoven fleece, woven fabrics, cotton, wool, synthetic fibers, and/orcellulose materials.

[0036] The sole 5 may be made from waterproof materials such as, forexample, rubber, polyurethane, polyvinyl chloride and their derivatives,and mixtures of the same.

[0037] The functional layer of a waterproof, water vapor permeablelaminate may be manufactured from polymers which are suitable forforming a microporous polymeric matrix. See, for example, U.S. Pat. No.5,732,479, incorporated by reference herein its entirety. Suitablepolymers include polyolefines, such as polyethylene-propylenecopolymers, polyethylene, terephthalates, polycaprolactam,polyvinylidenefluoride, polybutyleneterephthalate, polyester copolymersand polytetrafluoroethylene. A waterproof, water vapor permeablefunctional layer may also be a coating or an impregnation or a membraneof the aforementioned polymers on a copolyether ester base, or may bemade of oriented polytetrafluoroethylene, preferably with a microporouspolyurethane coating (Gore-tex). Polymers of a copolyether ester base(Sympatex) have proved to be excellent materials for this purpose due totheir properties of high water vapor permeability, high waterproofnessand wear resistance.

[0038] The waterproof, water vapor permeable functional layer, alsoreferred to herein as “the functional layer”, is preferably formed bydipping a form into a solution or dispersion of a waterproof, watervapor permeable polymer and allowing the polymer to harden, and thenpeeling the functional layer from the form. The dipping process may berepeated several times. After dipping and before removal from the form,the polymer dispersion on the form may be heated, causing the polymer tomelt and form a continuous film. The form may roughly be in the shape ofa human foot or other three dimensional, solid article that would confera sock-like shape to the functional layer. Manufacture of the functionallayer may be accomplished using the methods and materials as describedin EP 0 665 259 A1 or in WO 95/30793, both of which are incorporatedherein by reference in their entireties.

[0039] The waterproof, water vapor permeable polymer solution ordispersion may contain copolyether esters obtained by copolymerizing anaromatic dicarboxylic acid or ester forming equivalent thereof with adioic acid molecular weight of not more than 300, a diol or esterforming equivalent thereof with a dioic molecular weight of not morethan 250, and a polyalkylene oxide glycol with a molecular weight in therange of 600 to 4,000 and an atomic ratio of carbon to oxygen in therange of 2.0 to 4.3 with at least 20% by weight of the long chain glycolhaving a carbon to oxygen ratio in the range of 2.0 to 2.4 and 15% to50% by weight being part of the copolyether ester. The aromaticdicarboxylic acid preferably is terephthalic acid or napthalenedicarboxlyic acid, while the low-molecular weight diol preferably isethylene glycol or butane diol. In addition, preference is given to apolymer having a melting point of at least 150° C. See for example, EP 0665 259.

[0040] The sock-like functional layer may be made by dipping the forminto more than one dispersion or solution of polymers that each possessdifferent qualities to provide and/or improve the waterproof, watervapor permeable characteristics of the sock-like liner. By usingdifferent solutions or dispersions, a composite sock-like functionallayer may be formed. The first layer of the composite may be amicroporous, elastomeric, thermoplastic polyester polyurethane orpolyether polyurethane that is water vapor permeable. The second layeror subsequent layers of the composite may be a non-porous layer that ishydrophilic, waterproof, and water vapor permeable. The second layer orsubsequent layer may improve the waterproofness and/or water vaporpermeability of the first layer or impart other desired characteristics,such as wear resistance. The preferred polyurethanes for the first layerare elastomeric polyurethanes based on a linear, hydroxyl terminatedpolyester (although a polyester polyol or a polyether/polyester blendmay be used) and a diisocyanate, with a small addition of a difunctionallow molecular weight reactant.

[0041] The second hydrophilic polymer layer of the composite may be madefrom hydrophilic elastomers such as, for example, polyesters,polyamides, cellulose derivatives, polyacrylic acid and its homologs,natural or synthetic rubber with hydrophilic impurities, copolyoxamides,polyureas, polyelectrolytes, polyphosphates, polyvinylamines,polyvinylalcohol, polyether and copolymers thereof; polythioether,polythioether-polyether, copolyepichlorohydrinether, polysulphosphates,copolyesterether and derivatives or mixtures thereof Preferably thehydrophilic polymer is a copolyether ester, polyurethane or acopolyetheresteramide. All of these polymers are permeable to watervapor, but are highly impervious to liquid water. See, for example, WO95/30793, herein incorporated by reference in its entirety.

[0042] The sock-like functional layer may have a thickness of, forexample, about 10 to 150 microns. Preferably, the functional layer has athickness of, for example, about 40 to 100 microns. The sock-likefunctional layer may be formed dipping, spraying or any other process,well known in the art, of applying a dispersion or solution to a form orthree-dimensional article.

[0043] In another embodiment of the present invention, the adaptabilityof the functional layer may be increased by cutting an opening in thebottom of the functional layer 2. As shown in FIG. 3, by making a cut inthe bottom of the functional layer, for example, along line 7 and thusforming cut ends 13 a and 13 b as shown in FIG. 4, it is possible toadapt the shape of the functional layer 2 to a variety of shoe sizes. Asshown in FIG. 4, the cut ends 13 a and 13 b of the functional layer 2may then be bonded together with glue and/or with a seam 8. As shown inFIG. 5, the connection between the cut ends 13 a and 13 b may be madewatertight by tightening the cut ends 13 a and 13 b over a tape 9 andover glue 10. If cut ends 13 a and 13 b are too long after rejoining,removing a portion of the functional material along the cut or cuttingthe excess length of the cut ends may provide for a smaller sock-likefunctional layer, further increasing the adaptability of the sock likeliner to an even greater variety of shoe sizes.

[0044] In another embodiment, an insole 11 may be incorporated with thesock-like functional layer. As shown in FIG. 6, the functional layer 2is cut out in the bottom area (i.e., the surface of the functional layerwhich would have been adjacent to the sole) and removed. The ends of thefunctional layer, made by cutting out the bottom area, are preferablybonded to the edges of the insole over seams 12. The connection betweenthe functional layer and the insole may be made waterproof if the endsof the functional layer and the insole are connected in a manneranalogous to FIG. 5, i.e., the functional layer and the insole areconnected over glue and tape. The functional layer, insole and upper maybe joined to the sole by, for example, gluing, sewing, adhesives,injection molding, or other techniques.

[0045] The functional layer, after having an insole inserted, a cut madealong line 7 to increase the adaptability of the shoe, or othermodification which might have breached the waterproof, water vaporpermeable properties of the shoe, may have the solution or dispersion ofwaterproof, water vapor permeable polymer reapplied to the functionallayer to regain or improve the waterproof, water vapor permeableproperties of the functional layer.

[0046] As shown in FIG. 1, the glue used to attach the bottom of theshoe to the upper and functional layer may provide a sealant for the anyseams between the sole, the upper and the functional layer. This gluedconnection may also seal any seams or breaches in the functional layercreated from having an insole inserted., a cut made along line 7 toincrease adaptability or other modification. It is also possible tofirst glue the seams between the functional layer and the upper to makethe seams watertight and then to glue the sole to the bottom of theupper and the functional layer.

What is claimed is:
 1. A waterproof, water vapor permeable shoeconstruction comprising: a waterproof, water vapor permeable functionallayer; an upper; and a lining; wherein the waterproof, water vaporpermeable functional layer is situated between the upper and the liningand is attached to the lining only at a top portion of the upper at anopening of the shoe construction where a foot would enter.
 2. Thewaterproof, water vapor permeable shoe construction of claim 1, whereinthe upper is folded over the functional layer and lining at the topportion of the upper to form the attachment between the functional layerof the lining.
 3. The waterproof, water vapor permeable shoeconstruction of claim 1, further comprising a sole.
 4. The waterproof,water vapor permeable shoe construction of claim 3, wherein the sole isattached to the functional layer and the upper.
 5. The waterproof, watervapor permeable shoe construction of claim 3, wherein the outerperimeter of the sole is sewn to the functional layer and the dispersionor solution of the waterproof, water vapor permeable polymer isreapplied to the sewn portions of the functional layer.
 6. Thewaterproof, water vapor permeable shoe construction of claim 3, whereinthe sole is injection molded and the functional layer is bonded to thesole.
 7. The waterproof, water vapor permeable shoe construction ofclaim 1, wherein an opening, having cut ends, is cut in the bottom ofthe functional layer and a seam is formed joining the cut ends of theopening.
 8. The waterproof, water vapor permeable shoe construction ofclaim 7, wherein portions of the functional layer at the cut ends areremoved before the seam is formed joining the cut ends.
 9. Thewaterproof, water vapor permeable shoe construction of claim 1, whereinthe bottom of the functional layer is removed and an insole is joined tothe functional layer.
 10. A method of manufacturing a waterproof, watervapor permeable shoe, comprising: forming a waterproof, water vaporpermeable functional layer in the shape of a sock from a dispersion orsolution of a waterproof, water vapor permeable polymer; inserting thewaterproof, water vapor permeable functional layer into an interior of ashoe; inserting a lining into the waterproof, water vapor permeablefunctional layer; and attaching the waterproof, water vapor permeablefunctional layer to the lining only at the top opening of the shoe.